symbolic differentiation of unknown function
I want to do some formal calculus with unknown functions for the purpose of solving differential equations.
Say F(t) = v(t)*t^2
, where v
is an unknown differentiable function.
Then I would like to declare v
as such and be able to get
F.diff(t) = 2*t*v+t^2*v.diff(t)
It is similar to Ask Sage question 8822
but the solution does not seem to work anymore, as function()
takes
only one argument and not 2 as in the description.
Anyone know what the syntax is in 8.9? Or in 9.0, when that becomes available?
Note: I updated the answer to Ask Sage question 8822.